It is well known that there is a need for effective preservatives in a wide variety of applications where inhibiting the growth of microorganisms is necessary, as for example, personal care products such as shampoos, creams, lotions, cosmetics, liquid soaps, and household products such as fabric cleaners and softeners, hard surface cleaners and the like. The shelf life of these preparations depends on their resistance to microbial spoilage. In addition, antimicrobial agents are a matter of substantial commercial importance in many industrial applications and products such as in paint, wood, textiles, adhesives and sealants, leather, plastics, oil, rubber and metal working fluids etc.
Certain compounds have long been known and used commercially as preservatives. For example, 1,3-dimethylol-5,5-dimethylhydantoin (DMDMH) is useful as a formaldehyde donor for the preservation of personal care products, cosmetics and household products and halopropynyl carbamates are known for their fungicidal activity. Other commercially known preservatives include Quaternium-15 (DOWICIL 200 from Dow Chemical Company); Imidazolidinyl urea (GERMALL 115 from Sutton Laboratories); formaldehyde in the free state, as in formalin; alkyl parabens (e.g. methyl, ethyl and propyl) etc. While such materials have achieved commercial acceptance for many personal care and household products, they generally present a variety of limitations for such use including being unduly expensive; exhibiting limited anti-microbial or antifungal activity, or limited solubility in water; exhibiting undue pH dependence, adverse toxicological properties and skin sensitization or possible carcinogenicity; or they may be inactivated by commonly used materials.
Various synergistic combinations of ingredients have been also suggested for use as preservatives in certain applications such as, for example, disclosed in U.S. Pat. Nos. 3,699,231; 3,929,561; 4,454,146; 4,655,815; but these compositions generally exhibit unfavorable toxicity characteristics, particularly skin and eye irritation, and are not suitable for personal care and household products, and the development of effective, inexpensive, multifunctional products having a broad spectrum activity has long been sought.
U.S. Pat. No. 5,648,348 issued July 1997 to Fost et al discloses phospholipid based quats useful as antimicrobial. This patent, incorporated herein by reference, teaches that phospholipids can be employed as antimicrobials. These products contain phosphorus an element that has been implicated in blooms of algae in rivers and streams, making them very undesirable with today's environmentally concerned consumer.
It is highly desirable to have a product that is phosphate free for environmental reasons, is effective at controlling microbes and provides the cosmetic formulator with other formulation benefits in addition to preservation. One such example is if a molecule not only acts as a preservation system, but also provides conditioning in shampoos. The preservative in most cosmetic systems does nothing else but preserve the product from microbes, and is an expensive part of the formula. The compounds of the present invention provide conditioning, and outstanding wetting properties, are inherently non-toxic and non irritating.
None of the patents referenced above provide for such a multifunctional product. It was not until the present invention that all these desirable attributes were found in a single molecule.